Shock-absorbing mechanism for railway-cars.



C. K. BROOKS ci. E. H. SCHMIDT.

SHOCK ABSORBING MECHANISM.

APPLICATION FILED APR.26. i916. RENEWED SEPT.25. 1918.

FLSLSOQ, Patented Apr. 291. M9.

2 SHEETS-SHEET 1. m

venom T sa'rns an nic CHESTER K. BROOKS, OF MENTOR, AND ERNEST H. SCHMIDT, OF CLEVELAND, OHIO,V

ASSIGNORS TO THE NATIONAL MALLEABLE CASVTINGS'COMPANY, OF CLEVELAND,

OHIO, A CORPORATION OF OHIO.

racines..

Specification of Letters Patent.

'Patented am. zo, rois.

Application led April 26, 1916, Serial No. 93,596. Renewed September 25, 1918, Serial No. 255,695.

`jointly invented new and useful mprovef ments in Shock-Absorbing IMechanism for Railway-(lars, of which, the following is a specification, reference being had to the accon'ipanying drawings, in which- Figure l is a plan, partly in section, showing an embodiment of our invention applied to nthe underframing of a car; Fig. 2 ,is a sec-` tion on lines II--ll of Fig. 1; Fig. 3 is a section of a modified form of our device; Fig. 4f is a plan, partly in section, of this modification; Fig. 5 is a diagrammatic section of another modified form of wedge,

.shoes and cent al member; Fig. (3 Vis a diagrammatic section of another modified form of wedge, shoes and central member, and Fig. 7 is a further modification of the wedge and slices.

@ur invention relates to shock absorbing or cushioning mechanism, and is particularly adaited for use on railway cars, and consists of an included friction member, friction shoes arranged therearound, and wedging means adapted to press the shoes against the included friction member and drive them longitudinally thereof. Our in vention also consists in the construction and cooperation of the parts, which we shall hereinafter describe and claim.`

Referring to the embodiment of our in vention set forth in F igs. 1 and 2 (if the drawings, the included. or central friction menrber 2 has preferably a plural ity-of longitudinally-extenchng circumferentially and ladially disposed arms 3, which have at their sides friction faces. lBetween eachadjacent pair of arnls 3 is mounted a friction shoe 4, the faces 4 of which engage the friction faces on the arms. In Figs. 1 and 2 we have shown one set of friction shoes, consisting preferably of four slices. The fric* tion shoesrs are held in position by a pair of .wedges 5 and 6, each of which. is in the form of a ring kcut away at the center for the passage of the member 2. T he wedge 5,

which also acts as the front follower, has inclined faces each of wlneliengages 4a compression of the spring 1l.

co1'res1 ondingly inclined face Ll"l on a friction shoe 4. The inner wedge (S, which acts as the spring follower, also has inclined faces (3"4 each. of which engages a correspondingly inclined face if on a friction shoe. The arms 3 of the central member 2Q are tapered somewhat in a longitudinal direction, the arms at the point 8 being somewhat thicker than at their forward ends. To the rea'r of the frictional surfaces of the arms, the central portion and the arms are preferably reinforced as at 9, to provide additional strength and to distribute more evenly the pressure from the central mem ber through its enlarged rear or base portion 10 to the car.- The base 1l) is suitably formed on its iner face to provide a bearing for a compression spring 11, which encircles the member 2, and at. itsI forward end bears against the rear face of the wedge The parts just described may, if desired, be contained in a casing 12, closed at its end 13 and affording a` bearing for the base 10, which is held against the end 18 by the l2, atl its rear end, is preferably enlarged to provide a. bearing against the usual draft sill stops, and at its forward cnd has pockets or recesses 14 for the admission of the triangularlyshaped bracing ribs 15 on the outer wedge 5. This casing protects the frictional and spring parts of the rigging 'from Vshock in excess of their capacity, since the flanges 16 on the wedge follower 5 will strike against the edges of the open end of the casing to prevent the parts from` going' solid when they have 'reached the intended limit of travel.

lt has been found desirable to place the rigging in the yokeunder a moderatiI initial compression. to eliminateA any initial looseness of the parts. To this end we provide the central member 2 with a threaded hole 17 in its outer end, for the reception of a. bolt 20, which may beemployed tocplace the spring under the desired compression.

Vile have found that, in order to make the device of suitable wear-resisting qualities, smooth in operation, and of requisite frictional capacity, it is desirable to make the wedges, shoes and central member of materials of varying degrees of hardness. For instance, the central member 2, as it is a rThe casing.

the rigging, ismade with its friction surfaces of a hardness greater than that of the friction shoes il, so that the greater part of the Wear may occur 1apen the shoes, which, being; of simple form and relatively inexpensive to malte, are easily replaced when worn relatively llarge and expensive part of out. Als the wede members 5 and G are subjected to very great bursting stresses, they are made of a material of. great toughness and elasticity, and we therefore prefer to have the wedges of a softer material than either the shoes 4r. or central member 2, although goed results have been obtained with wedlsges which are harder than the slices.

.in the operation of the device, the outerH moet wedge 5, which may be formed as a follower, forces the shoes el, and with them the inner Wedge G, along the friction meinber 2, against the action of the spring l1, which bears against the inner Wedge G. "As the shoes travel along the friction surfaces on the arms 8 of the central member, the

taper of the arms of this member forces them outward radially or transversely of the line of longitudinal movement to an ei;- tent dependent on the amount of taper upon the arms of the central member. The .movement of the shoes in this radial direction is resisted by the grip of the wedging surfaces on the wedges, which results in a very intense pressure being exerted upon the shoes, urging them into frictional contact with the central member to a much greater extent than the mere wedging action alone. This outward transverse movement of the shoes causes their inclinedy faces to slide very slightly relatively to the wedging faces of the Wedges, and when the faces of the shoes are harder than the faces of the wedges, there will be a tendency of the shoe surfaces to cut into the faces of the wedges and to form shoulders or roughened portions on the faces of the Wedges. 1 Tnen any roughening.

of the Wedging faces of the wedges occurs, the freedom of Wedging action between the Wedges and shoes becomes impaired, the resistance developed by the frictlonal parts becomes erratic and uneven, and the capacity of the rigging is often seriously afT fee/ted thereby. To prevent the development of such roughness or cutting' between the Wedging surfaces we havemadc the faces of the softer anen1l ers'in this case thel Wedges-of lesser extent than the faces of the harder material-in this case the shoesso that the shoe surfaces overlap or extend beyond the surfaces on the wedges which they engage. lt willbe seen that, as thc shoes overlap the wedges, particularly at the edges' toward the spring, such cutting o1' roughening will not occur. Referring to Fig. 2, which shows the. shoes 4 engaging thei arms 3 of the central mel'nher .2` we also prefer to make the engaging; faces 4: of

sach shoes of lesser e-,tcnl laterally tha# the harder faces of the arms 2%, so that the arm faces'will not cut into and form shoulders on the surfaces of the relatively softer shoes. ln this case the formation of shoulders would not interfere with the wedfflng action 'as these are friction surfaces and not wedging surfaces, but we have found that the formation of shoulders on these friction faces is very detrimental to the 'capacity of the device in case a shoe becomes slightly shifted or displaced from its normal path of movement, andthereby loses its full frictional Contact, by reason of the formation of such shoulders.

As the front wedge 5 forces the shoes and 'rear wedge 6 along the central member, the

out Yard or transverse movement of the shoes (where the wedges are of relatively greater elasticity) also results in the elastic expansion of the wedees to a certain extent, which will serve to maintain an elastic wcdg'ing grip on the friction shoes, to reduce to some extent the slippage between the wedging faces of the shoes and .vedges.

ln Figs, 3 and -lis shown a modified form of our device, inv which 2 indicates the central friction member, prcferablyformed at its rear end into an enlarged plate or base 10., which is designed to abut against the nsual draft sill stops (not shown) attached to the car structure. The central member has two sets of friction shoes al. and el bearing' in the rentrant angles formed by its arn'is, and `there is a wedge ring 5 having inclined surfaces engaging the shoes l of one set, and a wedge 6 at its forward side engaging the slices el", and at its rear side having a wedging engagement with the shoes el of the second set, said wedges and. sets of shoes being arranged alternately and in tandem. The foremost wedge 5 prefeiably comprises the front follower, also intended to bear against draft sill stops. To the rear of the rearmost set of slices is an intermediate follower 7, which bears against said shoes at its forward side, and at its rear site against one end of a coinpression spring' 11. Said spring surrounds the central member Q as do the wedges 5 and (3 and the follower 7, and said spring bears at'its rear end against the forward face of the base 10. In this form of our device, as the angles of wedging engagement between shoes and wedges are relatively sharper than those of the form of. F ig. l and the taper of the arms of the central member 2" more gradual, we prefer to provide the release springs 13, which bear at one end against the base 10', and at their other ends against releasing plunging-z 19, which in turn abut against the' forward wedge 5 and after release of this wedge, against the second wedge 6. These release springs 18 assist the compression spring 11 in returning the i Reise-e ,wedging angle between shoes L2 and wedge blunt. (being somewhat similar to the angles shown iin Fig. l), which diminishes to some extent the outward expanding pressure. exerted by the shoes upon the Wedge. '.lhis pressure, however, is still sufficient .to cause the wedge to expand slightly, but, due to the excessive taper upon the member 22, the shoes will move outwardly to almuch greater extent than the wedge will expand. T he shoes will therefore move outward relatively to the wedge, as indicated by the arrows.l YVhen the shoes are of harder material than the wedge, is the case here illustrated, it is necessary to allow them to overlap the wedge in a direction toward the spring', which is the direction toward which relative movement'of the shoes occurswhen under pressure.

In the diagraunnalic representationof Fig. (3 we have shown a conditionIA opposite to that of Fin'. 5, and somewhat similar to that shown in Figs. 2S and fl. lhe acute wedding' angle between shoes 4:3 andwedge 51" throws a very great expansion stress upon the wedge, and this, in combination with the very slight taper upon thecentral member :23. by reason of which the transverse movement of the shoes is relativelysmall, results in a relative movement of the wedge over the shoes in a direction indicated bythe arrows. 1Qndcr these circumstances, the .relative movement of the shoes to the wedge takes place in a direction away from the spring and when the shoes are o a harder material than the wedge, as is the case here illustrated, it is necessary to allow them to overlap the wedge in that direction.

Both conditions illustrated in ligsf' and 6have been met in the operation of our improved device, and for this reason we have vfound it desirable to allow the harder member to overlap the softer, both toward and away from the spring, to take care of possible relative movement in eitherdirection.

ln Fig. 7 we have showin a further'niodificatiou 'of wedge 5* and slices t", inr which the harder member isy the wedge iand `the softer member is the shoe. ln thiscase the softer member, the shoe, is cut. away so as to permit the wedge to overlap each shoe.

lt will be understood that the above described relative movement between thc wedgingr surfaces on the shoes and wedges is extremely sn'iall in extent-so small as to be scarcely perceptible to the eye, and not at all comparable to the relative movement between tlie friction surfaces on the shoes and the Central friction member. Such movement between the wedging surfaces is small not only because of the relatively slight amount of taper on the arms of the central .member but also because the outward movement of the shoes is to a considerable extent ollfset by the outward expansion of the Wedge rings.

The terms and expressions which we have employed are used as terms of description and not of limitation, and We have no intention, in the use of such terms and expressions, of excluding any mechanical equivalent for the features shown and described, but recognize that various modilications are possible within the scope of the invention claimed.

What we claimv i:

1. ln friotional shock absorbing; mechanism, a longitudinallyextending included friction member having; a plurality of radiallydisposed arms, each arm having` longitudinally-tapered friction faces, a plurality of friction shoes arranged between said aims and in frictional engagement With'the side faces thereof, each shoe having;` an inclined wedgiingT face, and an integral wedge member encircling said included member and engaging the wedging faces of said shoes to compress the shoes againstthc included member, and a compression spring, the said shoes being adapted to be moved longitudinally of the included friction memberby a wedge, and to be moved transversely of the included lnen'iberby the taper on the arms thereof.

2. ln frictional shock absorbing mechanism, a longitudinally-extending included friction member having a plurality of radially-disposed arms, shoes arranged between said arms and in frictiional engagement with the side faces thereof, an integral Wedge member encircling` said included member and eng'aging'the wedding; faces of said shoes to compress the slices againsty the included member, and a compression spring, the arms of the included member increasing progressively in width toward the spring'.

Il. ln frictional shock absorbing mechanism. a central friction member having lon- ;itiulwilly-extending tapered friction faces, friction shoes erinaging` said faces, a wedge encircling said shoes and engaging); outer faces thereon and a .compression spring, the

/wedge being; a continuous unitary structure capable of expansion under pressure from the shoes.' when the shoes are moved laterally, and by its resistance to expansionv providinna an elastic grip upon the, shoes to 'minimize slippage of the wedging faces of the wedge relative to the wedging faces of the shoes.

Il. In frict-ional shock absorbing mechawedge nism, a eeinpressien spring, a longgitudinallyextending ineluded friction ineniber having1 a plurality of radially disposed arms, and a plurality of friction shoes arranged bctween said arlns .and in frictional engagement with the side faces thereof, each shoe having' a wedg'ing face, and an integral nieniber encircling` said included Inen'lber and engaging l'he wedging' faces of said shoes to compress Athe shoes anninsll the included ineinber, the engaging; faces of Wedge and shoes beine; of differing` hardness and the harder member havingits engaging face overlapping` and extending.;- beyond the engaging face of the softer member in the direction in which it moves away from such member, to prevent the harder lneniberfroin cutting' info the face of [he sofler nieinber.

ln friciennl shoelr absorhine; mechanism, a eoninression spring', a longitinflinallyexteni'ling included friction nieinber having` a plurality nf radially-disiwsed arms7 and a `plurality of friction shoes arranged between said arms and in frietienal engageinenl; with the said faces thereof5 each shoe hz'iving a Wedging face, and an integral wedge member encircling` said included lneinber and engaging the wedging facee of said shoes 'to coilmress the shoes against the included member, the engaging; faces nf the shoes being* of greater extent and of grcafer hardness 'than the engaging; faces of the Wedge, lo prevent the siees from curling info the faces 0f the wedge.

@Hlf TER it 

